class_docstr: Concept Activation Vector (CAV) is a vector orthogonal to the decision
  boundary of a classifier which distinguishes between activation
  vectors produced by different concepts.
  More details can be found in the paper:
      https://arxiv.org/abs/1711.11279
docstr: A utility function for creating the directories where the CAVs will
  be stored. CAVs are saved in a folder under named by `model_id`
  under `save_path`.
  Args:
      save_path (str): A root path where the CAVs will be stored
      model_id (str): A unique model identifier associated with the
              CAVs. A folder named `model_id` is created under
              `save_path`. The CAVs are later stored there.
docstr_tok: ["A","utility","function","for","creating","the","directories","where","the","CAVs","will","be","stored",".","CAVs","are","saved","in","a","folder","under","named","by","`","model_id","`","under","`","save_path","`",".","Args",":","save_path","(","str",")",":","A","root","path","where","the","CAVs","will","be","stored","model_id","(","str",")",":","A","unique","model","identifier","associated","with","the","CAVs",".","A","folder","named","`","model_id","`","is","created","under","`","save_path","`",".","The","CAVs","are","later","stored","there","."]
code: def create_cav_dir_if_missing(save_path: str, model_id: str) -> None:
      r"""
      A utility function for creating the directories where the CAVs will
      be stored. CAVs are saved in a folder under named by `model_id`
      under `save_path`.
      Args:
          save_path (str): A root path where the CAVs will be stored
          model_id (str): A unique model identifier associated with the
                  CAVs. A folder named `model_id` is created under
                  `save_path`. The CAVs are later stored there.
      """
      cav_model_id_path = os.path.join(save_path, model_id)
      if not os.path.exists(cav_model_id_path):
          os.makedirs(cav_model_id_path)
  
file_path: captum/captum/concept/_core/cav.py
imports: import os
  from typing import Any, Dict, List
  import torch
  from captum.concept._core.concept import Concept
  from captum.concept._utils.common import concepts_to_str
label_desc: Use image node_id 4 for calling the CAV obj's underlying member method code with example usage: obj.create_cav_dir_if_missing(save_path, model_id) without return types